Question

(i). यदि A, B और C त्रिभुज ABC के अंत:कोण हों, तो दिखाइए कि
sin(B+C/2)= cosA/2
​

Answer 1

Step-by-step explanation:

we know sum of triangles angles = π

therefore,

A+B+C = π

B+C = π-A...... @1

L. h. s

= sin((B+C)/2)

= PUT VALUE OF B+C FROM EQU. 1

= sin((π-A) /2)

= sin(π/2 - A/2)

= sin is in first quadrant.

= cosA/2

= RHS.